Bacteria-infecting viruses found on common bathroom items

The journal Frontiers in Microbiomes reports that over 600 types of viruses that infect bacteria (bacteriophages), many previously unknown, were found on toothbrushes and showerheads.

Researchers have long known that toothbrushes and showerheads can harbor bacteria originating from both users' mouths and municipal water systems. However, little was known about the presence of "bathroom" viruses.

Prior studies suggesting that flushing a toilet produces aerosols that carry bacteria inspired deeper research. These studies prompted Erica Hartmann from Northwestern University in Illinois to conduct new research. The team of scientists collected samples from 92 showerheads and 36 toothbrushes located in the bathrooms of people living in the USA.

Using DNA sequencing methods, researchers discovered that over 600 types of bacteriophages — viruses that infect bacteria — live on these surfaces. Interestingly, the majority were found on toothbrushes. It was fascinating to discover that almost every tested toothbrush was a habitat for different viruses.

Bacteriophages are viruses that infect bacteria but are harmless to humans. These viruses exhibit two mechanisms: taking control over bacteria to replicate themselves and kill the host, or integrating into the bacterial genome to change behavior. Scientists believe studying bacteriophages could lead to new ways to combat antibiotic-resistant bacteria.

The more you attack them with disinfectants, the more they are likely to develop resistance or become more difficult to treat. We should all just embrace them — said Erica Hartmann.

The researchers were particularly interested in mycobacteriophages, which infect mycobacteria, which are responsible for diseases like tuberculosis, leprosy, and chronic lung infections. Scientists hope mycobacteriophages could be used in the future to treat these dangerous infections and to purify water supply systems from hazardous pathogens.

The discovered bacteriophages likely occur in homes in bathrooms and other damp surfaces, such as sinks or refrigerator interiors. Nevertheless, researchers reassure that most are harmless.

There's no need to use aggressive disinfectants like bleach. To maintain showerheads, they can be submerged in vinegar to remove lime scale or simply cleaned with soap and water. It's worth remembering to change toothbrushes regularly.

Research by scientists from Northwestern University in Illinois sheds new light on the invisible world of microorganisms present in our homes. However, although microbes are commonly present, they rarely cause diseases. Excessive use of disinfectants may encourage the development of resistance in bacteria and various pathogens, making them harder to combat with antibiotics, which poses an increasing challenge to medicine.